Well drilling tool



Nov. 8, 1932. c. w. METZGER 1,886,570

WELL DRILLING TOOL Filed Dec. 13, 1927 5 Sheets$heet l INVENTOR 2 Nov. 8, 1932 (L w. METZGER WELL DRILLING TOOL .1927 3 Sheets-Sheet Filed Dec. 13

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Nov. 8, 1932. c. W/METZGER 1,336,570

WELL DRILLING TOOL Filed Dec. 15. 1927 3 Sheets-Sheet 3 INVENTOR: 26' W By i ATTORNEYS.

Patented Nov. 8, 1932 UNITED STATES PATENT OFFICE CLAUDE W. METZGER, OF HOUSTON, TEXAS, ASSIGNOR TO HAYNES STELLITE COMPANY, A CORPORATION OF INDIANA WELL DRILLING TOOL Application filed December 13, 1927. Serial No. 239,729.

This invention relates to well drilling tools and more particularly to an improved multibladed tool adapted for use in cable and rotary drilling operations.

Drilling bits heretofore in general use, particularly the fishtail type, are quite long when first manufactured so that they can be repeatedly re-dressed until they finally become unfit for further use. Such long bits are objectionable for several reasons: they have a tendency to wear unevenly and drill ofi' center, especially after they have been redressed in field shops where the steel is apt to be overheated and the edges are likely to be finished in varying thicknesses and shapes; also, it is impossible to properly supply water to the cutting edge at the lower end of a long bit. Special bits with water passages therein for this purpose are expensive and impractical.

The aims of this invention are to provide a well drilling tool that shall overcome the above and other objections; to provide a drilling tool in which the cutting blades are advantageously mounted and distributed upon the head, and readily removable and replaceable so that accurately finished and treated blades may be substituted for worn blades; and one in which the cutting edges are effectively cooled and freed from accumulated matter while in service.

Generally speaking, I provide a hollow drill head which is arranged to be coupled to a drill pipe or cable tool and is preferably cross-shaped in transverse section, so as to form four radial ribs with fluid channels lengthwise of its exterior surface between such ribs. These ribs have end and lateral seats to hold suitable cutting blades which will rapidly cut through any formation and guide the drill in the proper direction. A relatively short, thick, double-bladed fishtail bit is secured centrally in a transverse end seat, and perpendicular thereto are seats to retain a pair of blades having cutting edges along their lower and lateral edges. These lower cutting edges are a short distance back of the plane of the cutting edges of the fishtail bit, and the lateral edges project slightly outside the head. Two additional pairs of .lines IV IV and VV 'of Fig. 3, some of cutting blades having front and side cutting edges are mounted in lateral seats on the head, one pair in the longitudinal plane of the fishtail bit, and the other in a plane perpendicular thereto and coinciding with the longitudinal plane of the first pair of blades just back of the fishtail bit. The second pair of blades, i. e. those in the plane of the fishtail bit, have their front cutting edges back of the plane through the front edges of said first pair of blades and also behind the front end of the drill head, while the third pair of blades have their cutting edges back of a plane through the cutting edges of the second pair. Both the second and third pair of blades also have lateral cutting edges successively a greater distance from the axis of the head than the lateral cutting edges of the first pair. Suitable fluid, such as mudladen water, is supplied directly adjacent to the fishtail bit and to the first pair of blades adj olning it by a number of passages leading from a chamber in the head to the end face thereof. The cutting and reaming edges of the several blades are preferably formed of suitable hard wear-resistant metal or alloy which is fused into recesses or otherwise applied along such edges. For this purpose, I may use an alloy of the type disclosed in United States Patent No. 1,057,423; or I may use an alloy consisting essentially of tungsten carbide, known as Dynit.

The objects and novel features of this invention will be apparent'from the following description taken with the accompanying drawings, in which Figs. 1 and 2 are side views of an improved drilling tool embodying this invention, either one being a view taken 90 circumferentially around the head from the other;

Fig. 3 is an end view of the improved tool Figs. 4 and 5 are longitudinal sectiona views of the head of'the tool, taken on the the blades being omitted;

Fig. 6 is a perspective View of one of the first pair of blades; and

Fig. 7. is a perspective view of one of the second pair of blades, parts of this view being broken out to illustrate the application of wear-resistant metal to the cutting edges of the several blades including the fishtail bit. Referring to the drawings which illuctrate a desirable embodiment of this invention, H is a steel head that is provided with a thread.- ed tapering shank 10 whereby the head may be coupled to a rotary drill pipe or to a cable drilling stem. The head has a chamber 11 to receive water or mud-laden fluid from a suitable supply. The inner end of this chamber is enlarged, as shown, and has a number of outlet passages 12, 13, 14, 15 leading from its bottom and having orifices the front end of the head H, the passages 12, 13, being straight and parallel and passages 14, 15 being outwardly inclined in opposite directions.

Between its shank and its front end, the head is substantially cross-shaped to provide four radial ribs 16, 17 18 and 19 and channels C intermediate the:e ribs for the passage of mud-laden fluid lengthwise of the head. Perpendicularly intersecting outwardly-opening slots or recesses 20 and 21 are formed in the front end of the head, and the ribs respectively have central slots or recesses 16, 17,

18 and 19 extending lengthwise thereof. To simplify manufacture, the slots 16', 18..may be continuations of the slot 20, and the slots 17 19 continuations of the slot 21. These slots provide seats and their opposed walls abutments for the several removable and replaceable cutting blades which are symmetrically mounted at suitable places on the head to obtain the desired drilling and reaming action and to properly balance the tool so that it will drill a straight hole.

A fishtail bit F is removably seated in the slot 20 and is firmly secured in place therein by appropriate means. As shown, a tapering socket 22 is formed in the bottom of slot 20 at the intersection of the slots 20, 21 to receive the tapering shank 23 of this bit, and the opposing walls of the slot 20 provide abutments for the base of the bit. The shank 23.

has a V-sha'pe notch 23' to receive the end of a set screw 24 which may be screwed into threaded hole 24 that extends angula-rly from the bottom of the slot 21 to the socket 22. The set screw 24 thus engages the inclined face of the notch to draw the shank 23 into the socket 22 so that the shoulders 25 of the bit F will seat against the bottom of the slot 20. The bit F is rectangular and relatively short and thick; and comprises two blades F integrally united, offset from each other, and facing in opposite directions. The blades F have fiat front faces which are provided with end cutting edges 26 and lateral cutting edges 27, the body .of the hit back of the end cutting edges 26 being rounded offfor clearance, as shown at 26. The bit F is desirably a mas- I sive steel forgingwith wear-resistant metal fused or puddled into substantially triungular' recesses in its front faces along its end and lateral cutting edges, as shown by shade lines at 28, thereby eliminating frequent removal for redressing. and otherwise increasing the life of the tool and the speed of drilling.

The first pair of blades X, X is rigidly mounted in the slot 21 in a plane perpendicular to the bit F,one on each side of the latter. Each of these blades'has flat front face provided with a front cutting edge 29 and a lateral cutting edge 30, which edges are formed of wear-resistant metal by puddling the metal into triangular or other suitably shaped recesses, in the front face of the blade, as indicated by shading at 31'. The bases of the'blades X, X are disposed between opposed walls of the slot 21 to resist circumferential thrust against the blades, and each blade has a tapering shank 32 provided with a il-shape notch 32. Tapering sockets 33 are formed in the bottom of the slot 21 at opposite sides of and parallel to the socket 22 to receive the tapering shanks of the blades X, X. Set screws 84: extend through downwardly inclined holes 34 into the notches 32 to secure the blades X, X to their seats. The holes 34' are in opposite sides of the ribs 17 and 19, and open into the adjoining channels C so that the set screws therein will-be readily accessible to release or secure the blades.

The front cutting edges of the blades X, X are offset from each other, face in opposite directions, and are desirably in a plane a short distance behind the front cutting edges of the bit F. The lateralcutting edges of the blades X, X are also offset from each other and preferably project radially beyond the adjoining parts of the ribs so as to overhang part of the head and operate as reamers. These blades may also be ground oif behind their front and lateral cutting edges to provide clearance and so that they will be selfsharpening.

It will-be seen that the orifices of the fluid passages 12, 13 are directly in line with the front faces of the blades of the bit F, and that the orifices of the passages 14, 15 are alined with the front faces of the blades X, X. These passages extend through the side walls of the several slots and their orifices are thus brought relatively close to the several cutting edges of the bit F and blades X, X. These features. are of considerable practical importance because the force of the discharging fluid is thereby applied close to the cutting edges and is better able to cool them and to dislodge material adhering thereto.

A second pair of blades Y, Y is mounted on the head in a plane coincident with the bit F, one on each side of the latter. These blades are seated in recesses or slots '16, 18 which may be continuations of the slot 20 length: wise of the ribs 16, 18, a radial tapered socket 35 being formed at the'bottom of each of such slots to receive a t. ered lateral shank 36 on each blade. Suita 1e set screws 37 extend through threaded inwardly inclined holes 37 into the notches 36 of the shanks 36 to secure into a substantially triangular recess 40 on v the front face of the blade, as clearly shown in Fig. 7, and the blades may be ground off to a curved surface rearwardly of their cutting edges, as in the case of the blades already described. The front cutting edges 39 of these blades are desirably in a plane behind that containing the cutting edges 29 of the blades X, X, and their lateral cutting edges 38 may provide reamers projecting radially farther outside the head than the edges 30 of the blades X, X. Moreover, the inner ends or bases of the blades Y, Y bear against abutments formed by the opposing walls of the recesses in which they are seated.

In order to firmly secure th blades Y, Y in their seats and to support them against end thrust, where the slots extend the full length of the ribs, I may secure abutment blocks 42 in the slots behind the blades. These blocks engage the lower ends of the blades and may be secured in the slots 16, 18' as by shanks 42 thereon which have a drive fit with radial sockets 43 in the bottoms of the slots.

A third pair of blades Z, Z, similar in most respects to the second pair, may be secured, one on each side, to the head H in a plane e0 incident with the first pair X, X and in seats or slots 17 19 whichmay be continuations of the slot 21. The front faces of the blades Z, Z are offset from each other, the faces and cutting edges of the blades X and Z being in coincident planes and the same is true of blades X and Z. Similarly the end and lateral cutting edges 44 and 45 of the blades Z, Z are reinforced with a metal which is more wear-resistant than steel, such wear-resistant material being fused into substantially triangular recesses in the front faces thereof, as indicated at 46. Set screws 47 extend through inwardly inclined threaded holes 47 into notches 48 in the shanks 48 of the blades Z, Z to secure said shanks in tapered radial sockets 49 and to firmly hold these blades against their seats. The front cutting edges 44 of these blades are desirably in a plane behind that of the cutting edges 39 of blades Y, Y, and the lateral cutting edges 45 of the blades Z, Z may project radially a greater distance frornthe center of the head than those of the blades Y, Y, so as to function as reamers.

In the event that the slots 17, .19 extend the full length of the ribs 17, 19 and are open at the bottom, I may provide suitable means,

such as the abutment blocks 50 to engage and support the blades Z, Z attheir rear ends. These blocks as well as those for the blades Y, Y may snugly fit in the slots and-conform to the shape of the ribs, and similarly are secured in place by suitable means, as by shanks 51 having a drive fit in sockets 51 in the bottoms of the slots.

In order that the blades shall be'more easily removable, particularly when they have become wedged or rusted in their sockets and seats after a long period of service, I may drill holes 52 through the head, intersecting the sockets at their lower ends, to receive a drift pin or other suitable device to engage the rounded or otherwise inclined inner ends of the blade shanks to drive the shanks out of their sockets and loosen the blades from their seats. The drift pin holes 52 may be closed by suitable threaded caps 52 to keep them clear. v

The operation of the improved tool will be clear from the foregoing description. The blades remain serviceable for a much longer period than'those now in use because their cutting edges are of wear-resistant metal and are adequately cooled and'cleared of accumulated cuttings. T his eliminates frequent re moval for redressing, speeds drilling, and thus reduces the time and expense of drilling. When worn out, the blades may be readily replaced as desired by new blades accurately manufactured and heat treated, thus maintaining the hole true to gage and avoiding uneven wear, frequent and improper dressing, crooked hole and similar attendant difficulties encountered with drilling tools heretofore used.

I claim:

1. A well drilling tool comprising a head, longitudinal ribs extending along the side of said head and tapering towards the end of said drill, said ribs having slots therein, the end of said head having intersecting slots therein, a center bit secured in one of said end slots, blades secured in another end slot on opposite sides of said center bit and having end cutting edges in a plane behind the end cutting edges of said bit and side cutting edges extending beyond said ribs, other blades secured in said rib slots and having end cutting edges in a plane behind the end cutting edges of the first blades and having side cutting edges extending beyond said ribs.

2. A well drilling tool comprising'a tapering cross shaped head, the arms of said cross having longitudinal slots therein, the end of said head having intersecting slots extending between the ends of the arm slots, a center bit secured in one of the end slots, blades secured in the other end slot, one blade on 4 having end cutting edges in a plane behind the end cutting edges of said bit and having side cutting edges extending outside of the cross arms, and a pair of blades secured in opposite arm slots of each arm, each pair having end cutting edges arranged in successive planes behind the end cutting edge of the first blades and each pair having side cutting edges extending beyond the end of said cross arms.

3. A Well drilling tool comprising a head having an end face; said face having intersecting slots in-the surface thereof and an axial socket at theintersection of said slots a bit seated in one of said slots and a shank on said bit secured in said socket; said head having a hole extending an ularly from the bottom of a second one of said slots into said socket; a plug secured in said hole and bearing against said shank to secure said shank in said socket; and blades seated in said second slot, one blade on each side of said bit.

4. A Well drilling tool comprising a head having an end face provided With intersecting slots in the surface thereof; a center bit secured in one of said slots and extending across said intersection; a pair of blades secured in another of said slots, one blade on each side of and spaced from said bit, and

said blades having end cutting edges located at a greater radius from the center of the bit than the end cutting edges of said bit and located in a plane to the rear of the cutting edge of said bit.

In testimony whereof, I aflix my signature.

CLAUDE W. METZGER. 

